NAS Super-Low Noise Linear Power Supply

[WAD62]

Hi Will,
If a NAS supply is of poor quality any voltage variations on the supply line caused by noise, transient overshoot and ringing in the power supply system can feed through into the signal lines causing small errors in the digital stream waveform. These can translate into small timing errors, which is effectively adding jitter to the digital stream. Downstream equipment may not be able to reject incoming jitter effectively enough to render the jitter harmless. It is better to solve the problem at source rather than attempting to patch the problem at a later stage.

Hi Paul, I can absolutely understand that, in the case of PCM being streamed from the NAS, however in the case of a FLAC file being transfered via TCP/IP, into a player's buffer, for subsequent transcoding at the player end, I'm struggling...

Hence me asking if Marco transcoded at the NAS...

[Marco]

Could the improvement not be in NAS performance, or the Pi, but simply removing noise from the mains that the system uses ? This could be the source of the improvement that reduction in crap pumped into the overall mains supply that pre and power amps draw from.

Yes, that's already been considered and likely to partly explain the improvements gained.

Removing switched PSUs, particularly cheap nasty types supplied with hard drives, NAS etc is always a good thing. I get round it by having a separate spur isolated from where I hook up such crap PSUs. I have two dedicated mains outlets off a dedicated audio consumer unit and one general one coming off the house consumer unit for hooking PC, HD PSUs etc.

Smart move. I also do something similar.

The fact is, with increasing mobile phone usage, and the multitude of masts going up all over the place, to facilitate the demand (all generating RFI), together with many forms of modern electrical equipment using crappy switching PSUs, all plugged into and 'infecting' our mains supplies, not forgetting the deleterious noisy knock-on effects of the 'energy saving' lightbulbs most folks now use, the mains has never been more polluted - and things are only set to get worse!

I'm convinced it's one of the reasons why some hi-fi systems we remember listening to and sounding fab, 20-30 years ago, did so - a sound that we often struggle to replicate now, even with technically much better equipment........

Marco.

[tubehunter]

Some info on which this module is based:

http://www.amb.org/audio/sigma11/


Happy Days

[Spectral Morn]

Yes, that's already been considered and likely to partly explain the improvements gained.



Smart move. I also do something similar.

The fact is, with increasing mobile phone usage, and the multitude of masts going up all over the place, to facilitate the demand (generating RFI), together with many forms of modern electrical equipment using crappy switching PSUs, all plugged into and 'infecting' our mains supplies, not forgetting the deleterious noisy knock-on effects of the energy-saving lightbulbs most folks now use, the mains has never been more polluted - and things are only set to get worse!

I'm convinced it's one of the reasons why some systems we remember listening to and sounding fab, 20-30 years ago, did so - a sound that we often struggle to replicate now, even with technically much better equipment........

Marco.

Interesting thought.

[Marco]

Interesting thought.

As you know from experience, I'm capable of generating a few now and then! It's what comes from applying a little lateral thinking...

Marco.

[Marco]

Some info on which this module is based on

http://www.amb.org/audio/sigma11/

Interesting, Dunc, and also that MOSFETs feature prominently in the design

I'm trying to get Ian to abandon using his PC as a music storage device, and convert to off-board NAS units, powered by one of your linear PSUs. Tell 'im it makes sense!

Marco.

[Marco]

Good news also is that the components in the PSU are burning in now, and consequently it's getting even better!

Marco.

[TheFlash]

Could the improvement not be in NAS performance, or the Pi, but simply removing noise from the mains that the system uses ? This could be the source of the improvement that reduction in crap pumped into the overall mains supply that pre and power amps draw from.

Removing switched PSUs, particularly cheap nasty types supplied with hard drives, NAS etc is always a good thing. I get round it by having a separate spur isolated from where I hook up such crap PSUs. I have two dedicated mains outlets off a dedicated audio consumer unit and one general one coming off the house consumer unit for hooking PC, HD PSUs etc.

What he says^.

I have a dedicated mains feed to my modest system and could swear it makes a 5-10% (whatever that means - audible, basically) difference. My NAS sits on the general house supply, so the only way I would get an improved performance through running it off a linear PSU (as I do my Squeezebox and iRDAC which are on the dedicated mains) would be by somehow cleaning up the 0s and 1s being read off the drives and transmitted along the Cat6 cabling to the Squeezebox.

I struggle with how I might improve a stream of 0s and 1s, even if it's from a typically dirty house mains to a clean dedicated hifi one. Do the 0s and 1s change shape? Do extra ones sneak in? Do some of them get tired and give up on the journey? I genuinely "get" the benefits of linear PSUs over switched, I just can't apply that to a NAS as I can't see what it would change at the 0s and 1s level.

[Marco]

Can't really argue with that, Nigel, but then neither can I with the (very clearly audible) sonic improvements I'm hearing either, since installing the linear PSU....

Perhaps read what Paul Hynes had to say again on the subject, as he truly is an expert in PSU design, of all descriptions.

Marco.

[killie99]

I built a power supply, using an original AMB labs Sigma22 board, for my Project Phono RS phono stage. Make a big difference to the phono stage so I may build another one to power my RPi and SSD.